throw new IllegalStateException(ex.getMessage());
        }
    }

    protected byte[] engineDigest() {
        byte[] digest = md5.digest();
        md5.update(opad);
        return md5.digest(digest);
    }

    protected int engineDigest(byte[] buf, int offset, int len) {
        byte[] digest = md5.digest();
        md5.update(opad);
        md5.update(digest);
        try {

            throw new IllegalStateException(ex.getMessage());
        }
    }


    @Override
    protected byte[] engineDigest () {
        byte[] digest = this.md5.digest();
        this.md5.update(this.opad);
        return this.md5.digest(digest);
    }


    @Override
    protected int engineDigest ( byte[] buf, int offset, int len ) {
        byte[] digest = this.md5.digest();
        this.md5.update(this.opad);

    }

    /**
     * Completes the hash computation by performing final operations such
     * as padding. At the return of this engineDigest, the MD engine is
     * reset.
     *
     * @return the array of bytes for the resulting hash value.
     */
    public byte[] engineDigest () {
        // pad output to 56 mod 64; as RFC1320 puts it: congruent to 448 mod 512
        int bufferNdx = (int)(count % BLOCK_LENGTH);